Lubricant and process for making the same



Patented Apr. 15, 1941 4 2,238,478 LUBRICANT AND raocnss ron Mame THE same Emil Ott, Elsmere, Del., assignor to Hercules Powder Company, Wilmington, Del., a corporation of Delaware No Drawing.

Application March 4, 1939, Serial No. 259,799

23 Claims. (01. ask-42) This invention relates to an improved lubricant and coolant for use inmetal working and more particularly to an emulsified coolant for use in machining metals and alloys.

It is well known by those. skilled in the art that in machining metals the use of appropriatelubrication and cooling means is necessary for the production of high quality products. The art, therefore, when machining metals reduces the friction between the tool and the metal by using a lubricant and reduces the heat generated by absorbing it with the lubricant or with water which has been included with the lubricant. Thus the use of the proper lubricant and coolant facilitates speed, quality, and economy in the machining of metals or alloys and in the production of machined parts. Further the use of these lubricants or coolants protects and prolongs the life of the tools being used. The art uses many different lubricants and coolants among which, for example, are liquids comprised of vegetable oils and fats in admixture with mineral oils, soap solutions, and water-oil emulsions. The art usually uses a liquid as an aid in machining metals and alloys that has both the necessary lubricating and cooling properties de-. sired. These liquids may be composed largely of water, which due to its high specific heat al-.- lows the ready absorption of the heat generated by the friction between the tool and the metal, 1

with minor percents of lubricants and if neces-, sary emulsifying agents, but often the art uses light mineral oils alone as lubricants and coolant with good results. i

The object of this invention is to produce an improved coolant for use in machining metals. A-further object of this invention is to produce a coolant which will also act as a lubricant and will allow a higher speed of operation and feed in the machining of metals. A further object of this invention is to produce a coolant which will protect and prolong the life of the tools used in machining the various metals and alloys now used in the industry. A still further object of this invention is to produce a lubricant with a very high film strength. A still further objectof this invention is to produce a coolant which will more effectively wet the metal or alloy being machined. Other objects will appear hereinafter.

Now in accordance with this invention emulsions have been prepared which may be used as extremely efiective coolants. The emulsions include admixtures of alkylolamine esters of higher fatty acids with appropriate dispersing agents such as, for example, sulfonated oils, pine oil, or the like, and if desirable soaps such as sodium stearate, potassium stearate or the like.

The emulsions when used in specific machining operations may-also include vegetable, animal, or mineral oils depending upon the use for which the composition ,is intended. Thus the alkylolamine ester of a higher fatty acid is, in accordance with this invention, the active ingredient and, when admixed with dispersing oils and/or soap, a compound results which may' be called a soluble oil because of the ease with which it is emulsifiedin water. This soluble oil when agitated with water produces the lubricant or coolant of this invention. The coolants of this invention are prepared by admixing the prepared soluble oil into water with vigorous agitation or if desired, but not necessarily, emulsifying the soluble oil and water by passing it. through a colloid mill or a homogenizer.' The best results will be obtained by adding the soluble oil comprising an admixture of an alkylolamine ester of higher fatty acid, dispersing oils, and if desirable soaps, stepwise to the water volurne with constant agitation.

The allgvlolamine esters of higher fatty acids used as the active ingredient in the coolants of this invention may be prepared by heating an alkylolamine, for example, triethanolamine, diethanolamine, triisopropanolamine or' the like with a higher fatty acid such as, linoleic, lauric, ricinoleic acid, etc. or the glycerides thereof, for example, castor, olive, linseed, coconut, or like oils, under anhydrous conditions, to a temperature of about C. to about C. for a period of about 2 to about 30 hours. The heating period is preferably from about 4 to about 10 hours depending upon the temperature. It will be understood that when the above ester is prepared it is not necessarily a pure alkylolamine ester, but may contain small per cents of reaction byproducts such as glycerin or partially reacted glycerides and similar substances. Y

It will be understood that in accordance with this invention the term alkylolamine used above includes the various alkylolamines alone or in admixture with one another. Thus an alkylolamine may be a mono-,'di-, or polyalkylolamine, for example, mono-, di-, or triethanolamine or the similar methanolamines, propanolamines, glycerolamines, and the like. It will be appreciated that the alklylolamines may be used in admixture and that, for example, various polyalkylolamines will contain some mono-, and/ or di- 2 aasaava 1 allwlolamines especially where the commercial grade is used. Thus, for example, commercial triethanolamine, while it contains a preponderating proportion of triethanolamine. will also contain considerable quantities of mono-, and diethanolamine.

In accordance-with this invention two types of coolants may be prepared for use in machining metals. The ilrst type of coolant has a viscosity similar to that of water and is suitable for use in drilling, tapp w, grinding, and general cutting operations on the various metals and alloys. This first type coolant will be an aqueous emulsion containing about 1% to about 4% of a liquid which may include an alkylolamine ester of a higher fatty acid within the range of about 25% to about 60% in admixture with one or more dispersing oils, for example, pine oil, sulfonated castor oil, or the like. These mixtures may contain soaps to aid in emulsincation. but, as will be noted in the examples given hereinafter, soap and sulfonated castor oil may be substituted for one another. The second type of coolant is a heavy bodied emulsion and is suitable for use in tapping, turning, and similar operations. This second type coolant will be an emulsion containing about 4% to about 8% of an alkylolamine ester of a higher fatty acid. about 30% to about 40% water, with the remaining-percentages made up of one or more dispersing oils, for example, pine oil and sulfonated castor oil and one or more animal, vegetable, or mineral oils. This second type coolant may also contain small percentages of sodium oleate or similar soaps to aid in emulsifying the admixtures.

To illustrate the coolants of this invention, the composition and preparation of a few examples are shown below. The first nine examples are coolants having a viscosity similar to water while Examples. 10 and 11 are heavy bodied coolants.

Example 1 Partsby weight Triethanolamine-castor oil reaction prod-- uct Pine cii- 2e Neutralized sulfonated castor oil (65%) 50 1 .1 lum of this xture with 50 volumes m we v0 8 we The above reaction product which is crude of water.-

In the above example the reaction product prepared from an alkylolarnine and a higher fatty acid as indicated hereinbefore may be called the active ingredient while the admixture of this ester with the dispersing pile may be called the soluble oil and the diluted product is the lubricant and coolant of this invention.

Further examples are now given.

' agitation. The reaction 4 vigorous agitation.

Example 3 Parts by weight Triethanolamine-castor oil reaction product of Example 1.. 10 Neutralized sulfonated castor oil (85% 10 Water I Example 4 An alkylolamine ester of a higher fatty acid 10 was prepared by reacting one volume of commercial triethanolamine with two volumes of olive oil for 14 hours at 130 C. with vigorous product was used in An alkylolamine ester of a higher fatty acid was prepared by reacting one volume of commercial triethanolamine with one volume of- 5 cocoanut oil for 13 hours at 100 C. with vigorous agitation. The reaction product was used in preparing the coolant below.

Parts by weight Triethanolamine-cocoanut oil r e a c t i o n product 50 Pine oil 42. 5 Sodium oleate 5 Dilute as in Example 1.

Example 6 An alkylolamine ester of a higher fatty acid was prepared by reacting 78 parts by weight of triethanolamine (98% grade) and 437 parts by weight of oleic acid for 21 hours at 100 C. with The reaction product was used in preparing the coolant below.

7 Parts by weight Triethanolamine-oleic acid reaction product 50 Pine oil 42.5

Sodium olea 5 Dilute as in Example 1.

Example 7 An alkylolamlne ester of a higher fatty acid was prepared by reacting 240 parts by weight commercial triethanolamine with 750 parts by weight of Grade AA castor oil for 21% hours at 110 C. with vigorous agitation. The reaction was used in preparing the coolant below.

Parts by weight triethanolamine diricinoleate 25 Pine oil 25 Sulfonated castor oil 50 was prepared by reacting 201 parts by weight of commercial triisopropanolamine with 310 parts by 'weight of grade AA castor oil for 17 hours at 100 C. with vigorous agitation. The reaction product was used in preparing the coolant below.-

Parts by weight 'Iriisopropanolamine-castor 011 r e a 0 ti o n product p 50 Pine oil 85 Sodium oleate 10 Water- 4905 edge very few revolutions. When the "Hybnickel .alloywas-drilled using the coolant described in tion.

, An alkylolamine .ester of a higher fatty acid was preparedby reacting 158 parts by weight of commercial I-Idiethanolamine with 4'65 parts by weight-cf gradeAAcastor oil-for'4 hours at 100 with vigorous -agitation. .The reaction product'was used'in preparingflthe coolant below.-

. Partsbyweight Diethanolamine-castor foil reaction prod- ,uct I Y 50 Pine' oil w E125 .Sodium oleate- 5 Dilute as in Example 1.

' The following examples are of heavy bodiedcoolants which:are suitable for use in tapping,

turning, and like operations on metals. 7

The above t'e'sts, with the .coolant'ofExamples. 1 and 2' show deilnitely that the coolants in acccrdance'with this invention are much superior to the commercial coolants 'now' used by the art. Thecoolants oi thisinventionhave the following advantages over commercial coolants: -prolongingand protecting the life '0! the tools, the production of cool finished products, and the possibility of machining very toughor hardalloys. j

A further test with the coolant of Example 2 produced the similar superior result effected; in the preceding tests. Thus a test was made which consisted of drilling a 2' hole through a Example 10 I Percent Triethanolamine-castor oil reaction product -of. ample, .6-3 Pine 0 10.3 Sodium oleate 1.2 Raw-menhaden oil '5.9' Mineral oil (light bodie cylinder oil).... 41.2 Water Y -35.1

f R. P. M. and a feed of .003" which had satisof, Example 1..'. .8 Raw menhaden oil p 4.8 Pineoilv H 9.0 Sodium oleate ---.I '1.0 Cottonseed oil 43.8 water I 37.6 40

. -In -this example while emulsification' is possiblewwith vigorous agitation emu'lsiflcaticn in a colloid mill gives preferableresults.

The various coolants described in the above examples have been tested inmachining opera-' tions and have all been found superior to the coolants now used in the art. The coolants of this inventioncool and lubricate the tool and.

shown by the following tests: 1.

The nickel-base cast alloy HybnickeP' is so hard that with normal commercial coolants the of high-speed drills-are burned oif after 9.

Example 1 or 2; it was possible to drill through I and .005" feed without dull'ing the tool. To furthertest the coblant of Example 2, .a test was conducted on a nut cutting machine. The" nut blanks were being out from stainless steel (18% Cr8% Ni type) rod and the blanks dropping from the machine were cool enough to handle when the-coolant o'fExample 2 was used while they could not be touched if the'commercial coolants now known to the art were used. The coolant of Example 2 also kept the tool in working condition for a half day run whereas when commercial coolants are used the. toolmust be resharpenedjtwo or three times during a half day run. The coolant of Example 2 was also used to tapvthe nut blanks with the same excellent results obtained during the blank forming operasteeljblock using R. P. M. and-a feed. of .003", The coolant, Example 2, kept the tool sufhciently cool in the above operation to allow itto be graspedwith the barehand upon removal from the drilled hole while with commercial coolants the drill became so hot that it could not 'be touched. Further, the steel shavings when using the coolant of Example 2 are smooth and continuous thus producing .a smooth hole while withcommer'cial coolants .the steel shavings are rough and break into small'pieces which produce a rough hole that must be refinished 'after'the drilling operation.

Atest in which the heavy-bodied coolant of Example 10 was used shows that holes could tapped in- Va" steel, .at a drill 'speedof 80 factory threads. The same operation when using commercial coolantsproduces tapped holes in which the threads are so rough it is necessary to retap the holes by hand to produce a satisfactory product. v

Similar tests to those described above show.

that the coolantsgiven in the examples have many advantages, over the commercial coolants now known to the art. The use of coolants of this invention produces cooler and smoother work, provides" means whereby the machining operations may be speeded up, allows the. machining of various tough or hard metals or alloys,"and prolongs and protects the life of the .tools.

It will be understood that the details and examples given hereinbefore are illustrative only, and in no way limiting on my invention as broadly described hereinbefore-and in the appended claims.

What ,I claim and desire to protect by Letters Patent is:

. a casting with-a %"high speed'drill running at v 162 RP. M.

1. An aqueous emulsion coolant for use in metal working thatinludes an alkylolamine ester of a higher fatty acid and a dispersing agent.

' 2. An aqueous emulsion cooiantforuse in metal working that includes an alkylolamine ester vof a higher. fatty acid and a dispersing oil.

3. An aqueous emulsion coolant for usein metal working that. includes an alkylolamine ester of a .higher fatty acid, a. dispersing oil, and a soap.

l. An aqueous emulsion coolantfor use in metal workingthat includes an alkylolamine ester of a higher fatty acid and a mixture of sulphonated oil and pine oil.

5. An aqueous emulsion coolant for use in metal working that includes an alkylolamine ester of a higher fatty acid and a mixture of sulphonated castor oil and pine oil.

6. An aqueous emulsion coolant for use in metal working that includes a triethanolamine ester of a higher fatty acid and a mixture of sulphonated castor oil and pine oil.

7. An aqueous emulsion coolant for use in metal 4% of a liquid which includes an "ahl ifi fifitti acid and dispersing oil. 2 t a 9;";Ar 'oa'gueous emulsion coolant for"us e. in metal wo j m jthatfincludes an} ester obtained by the interaction oftriethanolamlne and castor oil and a dispersing oil.- i

- H 10. tngaqueous emulsion coolant use in 'metal working, that includes an ester obtained by the interaction'of triethanblamine and castor oil andja sulphonated vegetable oil. I 11, An;aqueous emulsionlcoolant for use in assay workingsthat includesan ester obtained by the c I int ra icnv i'tri tha q m a caster-01.1 a

"'offsulphonated castorioil and pine oil.

dispersing agent andemulsifylm the admixture in water. I 1 8. A method of preparing an aqueous emulsion coolant: including the stepsof, reacting on alkyl olamine to form'an esterfof a higher -fatty acid adding to the reaction productformed at least one dispersing agent, a-soap. 'andemulsifying 'theadinixture in water.

2 ii). A method of preparing an aqueous emulsion coolant including the steps of reacting an alkylolamine to form an ester of a higher fatty acid adding to the reaction product formed a mixture metalworking that includesan .esterobtained by the interaction of tri'etha'nolamine and castor oil and sulphonatedcastor oil.

12. an jaqus us emulsion [coolant for use, in' metal working'that includesan ester obtained by' 'the interactionof triethanolamine and castor oil,

adispersi'ng oilj'and a soap.

13.'An\,aqueou s emulsion coolant for use in metal working that includes an ester obtained by the interaction of triethanolamine and 'castor oil, pineoll; and asoap. .t

14. aqueous emulsion coolant for useln metal working, that includes an ester obtainedby the"interaction"' of trie'thanolamine and castor oil, pinefiil; and sodium oleate.

metal working that contains about 1% to about alkylolamine ester of a higher fatty acid within the range of about 25% to 60% in admixture with at least one dispersing agent. f t

16.-An,aqueous emulsion. coolant for use in metal working that contains about-4% to about 8%,of-an alkylola-mine ester of a higher fatty acid. about.30% to about 40% water and at least one dispersingagent. v

rll'lr a method of preparing an aqueous emulsion coolant :includingthe steps ofreactingan alkylolaminjeto form an esterpf'a higher fatty acid, adding to reaction product'formed at least one 30. An aqueous emulsion coolant for use in ofdispersing agents and emulsifying the admiigture in water. a t

A eth 0! Pr p ri g an aqueous emulsion coolant including the steps of reacting at between about 100 C. and about 130 C. an alkylolamine and ahigher fatty acid to form an ester of the higher fatty acid, adding to the reaction product formed at least one dispersing agent and emulsifying the admixture-in water; V

21. A method of preparing an aqueous emulsion coolant including the steps of reacting at between about 100 C. and about-130 C. for a period of about,2 hours to about hours an alkylolamine and a higher fatty acid to form an ester of the higher fatty acid, adding to the reaction product formed at least one dispersing agent and.

emulsifying the admixture in water.

22. A method of preparing an aqueous emulsion coolant including the steps of reacting at between about C.- and'130 C. an alkylolamine and a glyceride o'f ahigher fatty acid to form an ester reaction product, adding to the reaction product formed atleast one dispersing agent andemulsifying the mixture in water.

23. A methodof preparing an aqueous emulsion coolant including the-steps of reacting at between about 100 C. and- Q. for a period of about two hours to about thirty hours an alkylolamine and castor oil to form an ester reaction product, adding to the reaction product formed at least one dispersing agent and emulsifying the mixture Patent No. 2-:,258,) 7

CERTIFICATE OF CORRECTION.

' April 1 191,1.

7 EMIL OTT. It is hereby certified that error appears in 'the printed .specification of the above m'zmbered patent requiring correction as follows: Page 1, sec- I 7 0nd column, line 32, dfter" "ricinoleic" insert the comma and word -'-,oleic-;

and that the said Letters Patent ehouldbe read with this correction therein that the same may conform to the record of the case in the Petent Office.

Signed and sealed this 15th day of m A. D. 19t

'Henry Van Are dale (Seal) Acting Commissioner of Patents. 

